Providing single servings of cooled foods and drinks

ABSTRACT

Systems and methods have demonstrated the capability of rapidly cooling the contents of pods containing the ingredients for food and drinks.

RELATED APPLICATIONS

This patent application is a continuation-in-part of patent applicationU.S. Ser. No. 16/104,758, filed on Aug. 17, 2018 and claims the benefitof provisional patent applications U.S. Ser. No. 62/758,110, filed onNov. 9, 2018; U.S. Ser. No. 62/801,587, filed on Feb. 5, 2019; U.S. Ser.No. 62/831,657, filed on Apr. 9, 2019; U.S. Ser. No. 62/831,600, filedon Apr. 9, 2019; U.S. Ser. No. 62/831,646, filed on Apr. 9, 2019; andU.S. Ser. No. 62/831,666, filed on Apr. 9, 2019, all of which are herebyincorporated herein by reference in their entirety.

TECHNICAL FIELD

This disclosure relates to systems and methods for rapidly cooling foodand drinks.

BACKGROUND

Beverage brewing system have been developed that rapidly prepare singleservings of hot beverages. Some of these brewing systems rely on singleuse pods to which water is added before brewing occurs. The pods can beused to prepare hot coffees, teas, cocoas, and dairy-based beverages.

Home use ice cream makers can be used to make larger batches (e.g., 1.5quarts or more) of ice cream for personal consumption. These ice creammaker appliances typically prepare the mixture by employing a hand-crankmethod or by employing an electric motor that is used, in turn, toassist in churning the ingredients within the appliance. The resultingpreparation is often chilled using a pre-cooled vessel that is insertedinto the machine.

SUMMARY

This specification describes systems and methods for rapidly coolingfood and drinks. Some of these systems and methods can cool food anddrinks in a container inserted into a counter-top or installed machinefrom room temperature to freezing in less than two minutes. For example,the approach described in this specification has successfullydemonstrated the ability make soft-serve ice cream from room-temperaturepods in approximately 90 seconds. This approach has also been used tochill cocktails and other drinks including to produce frozen drinks.These systems and methods are based on a refrigeration cycle with lowstartup times and a pod-machine interface that is easy to use andprovides extremely efficient heat transfer. Some of the pods describedare filled with ingredients in a manufacturing line and subjected to asterilization process (e.g., retort, aseptic packaging, ultra-hightemperature processing (UHT), ultra-heat treatment,ultra-pasteurization, or high pressure processing (HPP)). HPP is a coldpasteurization technique by which products, already sealed in its finalpackage, are introduced into a vessel and subjected to a high level ofisostatic pressure (300-600 megapascals (MPa) (43,500-87,000 pounds persquare inch (psi)) transmitted by water. The pods can be used to storeingredients including, for example, dairy products at room temperaturefor long periods of time (e.g., 9-12 months) following sterilization.

Cooling is used to indicate the transfer of thermal energy to reduce thetemperature, for example, of ingredients contained in a pod. In somecases, cooling indicates the transfer of thermal energy to reduce thetemperature, for example, of ingredients contained in a pod to belowfreezing.

Some machines for producing cooled food or drinks from ingredients in apod containing the ingredients include: an evaporator of a refrigerationsystem, the evaporator defining a receptacle sized to receive the pod;and wherein the refrigeration system has a working fluid loop that runsfrom the evaporator to a compressor to a condenser to an expansion valveor capillary tube back to the evaporator and also includes a firstbypass line that extends from the working fluid loop between thecompressor and the condenser to the working fluid loop between theexpansion valve and the evaporator.

Some machines for reducing the temperature of ingredients in a podcontaining the ingredients and at least one mixing paddle include: anevaporator of a refrigeration system, the evaporator defining areceptacle sized to receive the pod; a motor operable to move the atleast one internal mixing paddle of a pod in the receptacle; wherein therefrigeration system has a working fluid loop that runs from theevaporator to a compressor to a condenser to an expansion valve back tothe evaporator and also includes a first bypass line that extends fromthe working fluid loop between the compressor and the condenser to theworking fluid loop between the expansion valve and the evaporator and abypass valve on the first bypass line.

Some machines for producing cooling ingredients in a pod containing theingredients and at least one internal mixing paddle include: anevaporator of a refrigeration system, the evaporator defining areceptacle sized to receive the single use pod; and a motor operable tomove the at least one internal mixing paddle of a pod in the receptacle;wherein the refrigeration system has a working fluid loop that runs fromthe evaporator to a compressor to a condenser to an expansion valve backto the evaporator and also includes a first bypass line that extendsfrom the working fluid loop between the compressor and the condenser tothe working fluid loop between the expansion valve and the evaporatorand a bypass valve on the first bypass line.

Some machines for producing cooling ingredients in a pod containing theingredients and at least one internal mixing paddle include: anevaporator of a refrigeration system, the evaporator defining areceptacle sized to receive the pod; and a motor operable to move theinternal mixing paddle of a pod in the receptacle; wherein therefrigeration system has a working fluid loop that runs from theevaporator to a compressor to a condenser to an expansion valve back tothe evaporator and also includes a first bypass line that extends fromthe working fluid loop between the compressor and the condenser to theworking fluid loop between the evaporator and the compressor.

Some machines for producing cooling ingredients in a pod containing theingredients and at least one internal mixing paddle include: anevaporator of a refrigeration system, the evaporator defining areceptacle sized to receive the pod; and a motor operable to move theinternal mixing paddle of a pod in the receptacle; wherein therefrigeration system has a working fluid loop that runs from theevaporator to a compressor to a condenser to a pressure vessel to anexpansion valve back to the evaporator and the working fluid loopincludes a first isolation valve between the pressure vessel and theexpansion valve and a second isolation valve between the compressor andthe condenser.

Some machines for producing cooling ingredients in a pod containing theingredients and at least one internal mixing paddle include: anevaporator of a refrigeration system, the evaporator defining areceptacle sized to receive the pod; and a motor operable to move theinternal mixing paddle of a pod in the receptacle; wherein therefrigeration system has a working fluid loop that runs from theevaporator to a compressor to a condenser to an expansion valve back tothe evaporator and the working fluid loop passes through athermoelectric cooler between the condenser and the expansion valve.

Some machines for producing cooled food or drinks from ingredients in apod containing the ingredients include: an evaporator of a refrigerationsystem, the evaporator defining a receptacle sized to receive the pod;and wherein the refrigeration system has a working fluid loop that runsfrom the evaporator to a compressor to a condenser to an expansion valveor capillary tube back to the evaporator; and wherein the evaporator ismade of a material that has at least 160 W/mK thermal conductivity.

Some machines for producing cooled food or drinks from ingredients in apod containing the ingredients include: an evaporator of a refrigerationsystem, the evaporator defining a receptacle sized to receive the pod;wherein the refrigeration system has a working fluid loop that runs fromthe evaporator to a compressor to a condenser to an expansion valve orcapillary tube back to the evaporator; and wherein a refrigerant isselected from the group consisting of R143A, R134a, R410a, R32 andR404a, carbon dioxide, ammonia, propane and isobutane.

Some machines for producing cooled food or drinks from ingredients in apod containing the ingredients include: an evaporator of a refrigerationsystem, the evaporator defining a receptacle sized to receive the pod;wherein the refrigeration system has a working fluid loop that runs fromthe evaporator to a compressor to a condenser to an expansionsub-system, comprising multiple orifices or expansion devices inparallel, back to the evaporator.

Some machines for producing cooled food or drinks from ingredients in apod containing the ingredients include: an evaporator of a refrigerationsystem, the evaporator defining a receptacle sized to receive the pod;wherein the refrigeration system has a working fluid loop that runs fromthe evaporator to a compressor to a condenser to an expansion valve orcapillary tube to a refrigerant line that pre-chills a tank of water,back to the evaporator.

Some machines for producing cooled food or drinks from ingredients in apod containing the ingredients include: an evaporator of a refrigerationsystem, the evaporator defining a receptacle sized to receive the pod;wherein the refrigeration system has a working fluid loop that runs fromthe evaporator to the one side of a thermal battery to a compressor to acondenser to the other side of a thermal battery to an expansion valveor capillary tube, back to the evaporator.

Embodiments of these machines can include one or more of the followingfeatures.

In some embodiments, machines also include a bypass valve on the firstbypass line.

In some embodiments, machines also include a second bypass line thatextends from the working fluid loop between the compressor and thecondenser to the working fluid loop between the evaporator and thecompressor. In some cases, machines also include a bypass valve on thesecond bypass line. In some cases, machines also include a suction lineheat exchanger.

In some embodiments, the working fluid loop passes through a reservoirof phase change material disposed between the compressor and thecondenser. In some cases, the phase change material comprises ethyleneglycol and water mixture, salt water, paraffin wax, alkanes, or purewater or a combination thereof. In some cases, the working fluid loopincludes a pressure vessel between the condenser and the evaporator, afirst isolation valve between the pressure vessel and the expansionvalve, and a second isolation valve between the compressor and thecondenser. In some cases, the working fluid loop passes through athermoelectric cooler between the condenser and the expansion valve.

In some embodiments, machines also include an aluminum evaporator with amass of not exceeding 1.50 pounds.

In some embodiments, machines also include a pressure drop through therefrigeration system less than 2 psi.

In some embodiments, machines also include a pod to evaporator heattransfer surface of up to 50 square inches.

In some embodiments, machines also include an evaporator has coolingchannels in it allowing for the fluid mass velocity up to 180,000lb/(hour feet squared) has refrigerant wetted surface area of up to 200square inches.

In some embodiments, machines also include an evaporator refrigerantwetted surface area of up to 200 square inches.

In some embodiments, machines also include an evaporator that clampsdown on the pod.

In some embodiments, machines also include an evaporator that has aninternal wall of copper adjacent to the pod.

In some embodiments, machines also include an evaporator that isconstructed of microchannels.

The systems and methods described in this specification can provide anumber of advantages. Some embodiments of these systems and methods canprovide single servings of cooled food or drink. This approach can helpconsumers with portion control. Some embodiments of these systems andmethods can provide consumers the ability to choose their single-servingflavors, for example, of soft serve ice cream. Some embodiments of thesesystems and methods incorporate shelf-stable pods that do not requirepre-cooling, pre-freezing or other preparation. Some embodiments ofthese systems and methods can generate frozen food or drinks fromroom-temperature pods in less than two minutes (in some cases, less thanone minute). Some embodiments of these systems and methods do notrequire post-processing clean up once the cooled or frozen food or drinkis generated. Some embodiments of these systems and methods utilizealuminum pods that are recyclable.

The details of one or more embodiments of these systems and methods areset forth in the accompanying drawings and the description below. Otherfeatures, objects, and advantages of these systems and methods will beapparent from the description and drawings, and from the claims.

DESCRIPTION OF DRAWINGS

FIG. 1A is a perspective view of a machine for rapidly cooling food anddrinks. FIG. 1B shows the machine without its housing.

FIG. 1C is a perspective view of a portion of the machine of FIG. 1A.

FIG. 2A is perspective view of the machine of FIG. 1A with the cover ofthe pod-machine interface illustrated as being transparent to allow amore detailed view of the evaporator to be seen.

FIG. 2B is a top view of a portion of the machine without the housingand the pod-machine interface without the lid.

FIGS. 2C and 2D are, respectively, a perspective view and a side view ofthe evaporator.

FIGS. 3A-3F show components of a pod-machine interface that are operableto open and close pods in the evaporator to dispense the food or drinkbeing produced.

FIG. 4 is a schematic of a refrigeration system.

FIGS. 5A and 5B are views of a prototype of a condenser.

FIG. 6A is a side view of a pod.

FIG. 6B is a schematic side view of the pod and a mixing paddle disposedin the pod.

FIGS. 7A and 7B are perspective views of a pod and an associateddriveshaft.

FIG. 7C is a cross-section of a portion of the pod with the driveshaftengaged with a mixing paddle in the pod.

FIG. 8 shows a first end of a pod with its cap spaced apart from itsbase for ease of viewing.

FIGS. 9A-9G illustrate rotation of a cap around the first end of the podto open an aperture extending through the base.

FIG. 10 is an enlarged schematic side view of a pod.

FIG. 11 is a flow chart of a method for operating a machine forproducing cooled food or drinks.

FIG. 12 is a schematic of a refrigeration system that includes anevaporator and an expansion sub-system.

FIG. 13 is a schematic of a refrigeration system that includes a bypassline that pre-chills a tank of water prior upstream of an evaporator.

FIG. 14 is a schematic of a refrigeration system that includes a thermalmass disposed between a compressor and a condenser.

FIG. 15 is a schematic of a refrigeration system that includes apressure vessel, a first control valve, and a second control valve.

FIG. 16 is a schematic of a refrigeration system that includes athermoelectric module.

FIG. 17 is a schematic of a refrigeration system that includes a thermalbattery, a first battery bypass valve, and a second battery bypassvalve.

FIG. 18A is top view of an evaporator cover 127 and FIG. 18B is a topview of the body of the evaporator.

FIGS. 19A and 19B are perspective views of an evaporator with andwithout an associated lid.

FIGS. 20A-20D are schematics of flow paths formed by the channels of theevaporator and an associated lid.

FIGS. 21A-21C are views of the pod and the evaporator of with a closingmechanism.

FIGS. 22A and 22B are side views of a closing mechanism that includes afirst bolt and a second bolt.

FIGS. 23A-23H illustrate an evaporator with an extruded body.

FIG. 24 illustrates an evaporator incorporating an orifice plate.

FIG. 25 is a perspective view of an evaporator, shown in FIGS. 19A and19B with an internal surface made of a different material than theevaporator.

FIGS. 26A-26C are schematic views of claddings.

FIG. 27 is an exemplary view of a material that includes microchannels.

FIGS. 28A-28C are top views of a rotary compressor.

Like reference symbols in the various drawings indicate like elements.

DETAILED DESCRIPTION

This specification describes systems and methods for rapidly coolingfood and drinks. Some of these systems and methods use a counter-top orinstalled machine to cool food and drinks in a container from roomtemperature to freezing in less than two minutes. For example, theapproach described in this specification has successfully demonstratedthe ability make soft-serve ice cream, frozen coffees, frozen smoothies,and frozen cocktails, from room temperature pods in approximately 90seconds. This approach can also be used to chill cocktails, createfrozen smoothies, frozen protein and other functional beverage shakes(e.g., collagen-based, energy, plant-based, non-dairy, CBD shakes),frozen coffee drinks and chilled coffee drinks with and without nitrogenin them, create hard ice cream, create milk shakes, create frozen yogurtand chilled probiotic drinks. These systems and methods are based on arefrigeration cycle with low startup times and a pod-machine interfacethat is easy to use and provides extremely efficient heat transfer. Someof the pods described can be sterilized (e.g., using retortsterilization) and used to store ingredients including, for example,dairy products at room temperature for up to 18 months.

FIG. 1A is a perspective view of a machine 100 for cooling food ordrinks. FIG. 1B shows the machine without its housing. The machine 100reduces the temperature of ingredients in a pod containing theingredients. Most pods include a mixing paddle used to mix theingredients before dispensing the cooled or frozen products. The machine100 includes a body 102 that includes a compressor, a condenser, a fan,an evaporator, capillary tubes, a control system, a lid system and adispensing system with a housing 104 and a pod-machine interface 106.The pod-machine interface 106 includes an evaporator 108 of arefrigeration system 109 whose other components are disposed inside thehousing 104. As shown on FIG. 1B, the evaporator 108 defines areceptacle 110 sized to receive a pod.

A lid 112 is attached to the housing 104 via a hinge 114. The lid 112can rotate between a closed position covering the receptacle 110 (FIG.1A) and an open position exposing the receptacle 110 (FIG. 1B). In theclosed position, the lid 112 covers the receptacle 110 and is locked inplace. In the machine 100, a latch 116 on the lid 112 engages with alatch recess 118 on the pod-machine interface 106. A latch sensor 120 isdisposed in the latch recess 118 to determine if the latch 116 isengaged with the latch recess 118. A processor 122 is electronicallyconnected to the latch sensor 120 and recognizes that the lid 112 isclosed when the latch sensor 120 determines that the latch 116 and thelatch recess 118 are engaged.

An auxiliary cover 115 rotates upward as the lid 112 is moved from itsclosed position to its open position. Some auxiliary covers slide intothe housing when the lid moves into the open position.

In the machine 100, the evaporator 108 is fixed in position with respectto the body 102 of the machine 100 and access to the receptacle 110 isprovided by movement of the lid 112. In some machines, the evaporator108 is displaceable relative to the body 102 and movement of theevaporator 108 provides access to the receptacle 110.

A motor 124 disposed in the housing 104 is mechanically connected to adriveshaft 126 that extends from the lid 112. When the lid 112 is in itsclosed position, the driveshaft 126 extends into the receptacle 110 and,if a pod is present, engages with the pod to move a paddle or paddleswithin the pod. The processor 122 is in electronic communication withthe motor 124 and controls operation of the motor 124. In some machines,the shaft associated with the paddle(s) of the pod extends outward fromthe pod and the lid 112 has a rotating receptacle (instead of thedriveshaft 126) mechanically connected to the motor 124.

FIG. 1C is perspective view of the lid 112 shown separately so the belt125 that extends from motor 124 to the driveshaft 126 is visible.Referring again to FIG. 1B, the motor 124 is mounted on a plate thatruns along rails 127. The plate can move approximately 0.25 inches toadjust the tension on the belt. During assembly, the plate slides alongthe rails. Springs disposed between the plate and the lid 112 bias thelid 112 away from the plate to maintain tension in the belt.

FIG. 2A is a perspective view of the machine 100 with the cover of thepod-machine interface 106 illustrated as being transparent to allow amore detailed view of the evaporator 108 to be seen. FIG. 2B is a topview of a portion of the machine 100 without housing 104 and thepod-machine interface 106 without the lid 112. FIGS. 2C and 2D are,respectively, a perspective view and a side view of the evaporator 108.Other pod-machine interfaces are described in more detail in U.S. patentapplication Ser. No. 16/459,176 filed contemporaneously with thisapplication and incorporated herein by reference in its entirety.

The evaporator 108 has a clamshell configuration with a first portion128 attached to a second portion 130 by a living hinge 132 on one sideand separated by a gap 134 on the other side. Refrigerant flows to theevaporator 108 from other components of the refrigeration system throughfluid channels 136 (best seen on FIG. 2B). The refrigerant flows throughthe evaporator 108 in internal channels through the first portion 128,the living hinge 132, and the second portion 130.

The space 137 (best seen on FIG. 2B) between the outer wall of theevaporator 108 and the inner wall of the casing of the pod-machineinterface 106 is filled with an insulating material to reduce heatexchange between the environment and the evaporator 108. In the machine100, the space 137 is filled with an aerogel (not shown). Some machinesuse other insulating material, for example, an annulus (such as anairspace), insulating foams made of various polymers, or fiberglasswool.

The evaporator 108 has an open position and a closed position. In theopen position, the gap 134 opens to provide an air gap between the firstportion 128 and the second portion 130. In the machine 100, the firstportion 128 and the second portion 130 are pressed together in theclosed position. In some machines, the first and second portion arepressed towards each other and the gap is reduced, but still defined bya space between the first and second portions in the closed position.

The inner diameter ID of the evaporator 108 is slightly larger in theopen position than in the closed position. Pods can be inserted into andremoved from the evaporator 108 while the evaporator is in the openposition. Transitioning the evaporator 108 from its open position to itsclosed position after a pod is inserted tightens the evaporator 108around the outer diameter of the pod. For example, the machine 100 isconfigured to use pods with 2.085″ outer diameter. The evaporator 108has an inner diameter of 2.115″ in the open position and an innerdiameter inner diameter of 2.085″ in the closed position. Some machineshave evaporators sized and configured to cool other pods. The pods canbe formed from commercially available can sizes, for example, “slim”cans with diameters ranging from 2.080 inches-2.090 inches and volumesof 180 milliliters (ml)-300 ml, “sleek” cans with diameters ranging from2.250 inches-2.400 inches and volumes of 180 ml-400 ml and “standard”size cans with diameters ranging from 2.500 inches-2.600 inches andvolumes of 200 ml-500 ml. The machine 100 is configured to use pods with2.085 inches outer diameter. The evaporator 108 has an inner diameter of2.115 inches in its open position and an inner diameter inner diameterof 2.085 inches in its closed position. Some machines have evaporatorssized and configured to cool other pods.

The closed position of evaporator 108 improves heat transfer betweeninserted pod 150 and the evaporator 108 by increasing the contact areabetween the pod 150 and the evaporator 108 and reducing or eliminatingan air gap between the wall of the pod 150 and the evaporator 108. Insome pods, the pressure applied to the pod by the evaporator 108 isopposed by the mixing paddles, pressurized gases within the pod, or bothto maintain the casing shape of the pod.

In the evaporator 108, the relative position of the first portion 128and the second portion 130 and the size of the gap 134 between them iscontrolled by two bars 138 connected by a bolt 140 and two springs 142.Each of the bars 138 has a threaded central hole through which the bolt140 extends and two end holes engaging the pins 144. Each of the twosprings 142 is disposed around a pin 144 that extends between the bars138. Some machines use other systems to control the size of the gap 134,for example, circumferential cable systems with cables that extendaround the outer diameter of the evaporator 108 with the cable beingtightened to close the evaporator 108 and loosened to open theevaporator 108. In other evaporators, there are a plurality of bolts andend holes, one or more than two springs, and one or more than engagingpins.

One bar 138 is mounted on the first portion 128 of the evaporator 108and the other bar 138 is mounted on the second portion 130 of theevaporator 108. In some evaporators, the bars 138 are integral to thebody of the evaporator 108 rather than being mounted on the body of theevaporator. The springs 142 press the bars 138 away from each other. Thespring force biases the first portion 128 and the second portion 130 ofthe evaporator 108 away from each at the gap 134. Rotation of the bolt140 in one direction increases a force pushing the bars 138 towards eachand rotation of the bolt in the opposite direction decreases this force.When the force applied by the bolt 140 is greater than the spring force,the bars 138 bring the first portion 128 and the second portion 130 ofthe evaporator together.

The machine 100 includes an electric motor 146 (shown on FIG. 2B) thatis operable to rotate the bolt 140 to control the size of the gap 134.Some machines use other mechanisms to rotate the bolt 140. For example,some machines use a mechanical linkage, for example, between the lid 112and the bolt 140 to rotate the bolt 140 as the lid 112 is opened andclosed. Some machines include a handle that can be attached to the boltto manually tighten or loosen the bolt. Some machines have a wedgesystem that forces the bars into a closed position when the machine lidis shut. This approach may be used instead of the electric motor 146 orcan be provided as a backup in case the motor fails.

The electric motor 146 is in communication with and controlled by theprocessor 122 of the machine 100. Some electric drives include a torquesensor that sends torque measurements to the processor 122. Theprocessor 122 signals to the motor to rotate the bolt 140 in a firstdirection to press the bars 138 together, for example, when a pod sensorindicates that a pod is disposed in the receptacle 110 or when the latchsensor 120 indicates that the lid 112 and pod-machine interface 106 areengaged. It is desirable that the clamshell evaporator be shut andholding the pod in a tightly fixed position before the lid closes andthe shaft pierces the pod and engages the mixing paddle. Thispositioning can be important for driveshaft-mixing paddle engagement.The processor 122 signals to the electric drive to rotate the bolt 140in the second direction, for example, after the food or drink beingproduced has been cooled/frozen and dispensed from the machine 100,thereby opening the evaporator gap 134 and allowing for easy removal ofpod 150 from evaporator 108.

The base of the evaporator 108 has three bores 148 (see FIG. 2C) whichare used to mount the evaporator 108 to the floor of the pod-machineinterface 106. All three of the bores 148 extend through the base of thesecond portion 130 of the evaporator 108. The first portion 128 of theevaporator 108 is not directly attached to the floor of the pod-machineinterface 106. This configuration enables the opening and closingmovement described above. Other configurations that enable the openingand closing movement of the evaporator 108 can also be used. Somemachines have more or fewer than three bores 148. Some evaporators aremounted to components other than the floor of the pod-machine interface,for example, the dispensing mechanism.

Many factors affect the performance of a refrigeration system. Importantfactors include mass velocity of refrigerant flowing through the system,the refrigerant wetted surface area, the refrigeration process, the areaof the pod/evaporator heat transfer surface, the mass of the evaporator,and the thermal conductivity of the material of the heat transfersurface. Extensive modeling and empirical studies in the development ofthe prototype systems described in this specification have determinedthat appropriate choices for the mass velocity of refrigerant flowingthrough the system and the refrigerant wetted surface area are the mostimportant parameters to balance to provide a system capable of freezingup to 12 ounces of confection in less than 2 minutes.

The evaporators described in this specification can have the followingcharacteristics:

TABLE 1 Evaporator parameters Mass Velocity 60,000 to 180,000 lb/(hourfeet squared) Refrigerant Wetted Surface Area 35 to 200 square inchesPressure drop Through less than 2 psi pressure drop across theRefrigeration Process evaporator Pod/Evaporator Heat 15 to 50 squareinches Transfer Surface Mass of Evaporator 0.100 to 1.50 pounds MinimumConductivity 160 W/mK of the MaterialThe following paragraphs describe the significance of these parametersin more detail.

Mass velocity accounts for the multi-phase nature or refrigerant flowingthrough an evaporator. The two-phase process takes advantage of the highamounts of heat absorbed and expended when a refrigerant fluid (e.g.,R-290 propane) changes state from a liquid to gas and a gas to a liquid,respectively. The rate of heat transfer depends in part on exposing theevaporator inner surfaces with a new liquid refrigerant to vaporize andcool the liquid ice cream mix. To do this the velocity of therefrigerant fluid must be high enough for vapor to channel or flow downthe center of the flow path within the walls of evaporator and forliquid refrigerant to be pushed thru these channel passages within thewalls. One approximate measurement of fluid velocity in a refrigerationsystem is mass velocity—the mass flow of refrigerant in a system perunit cross sectional area of the flow passage in units of lb/hrft{circumflex over ( )}2. Velocity as measured in ft/s (a more familiarway to measure “velocity”) is difficult to apply in a two-phase systemsince the velocity (ft/s) is constantly changing as the fluid flowchanges state from liquid to gas. If liquid refrigerant is constantlysweeping across the evaporator walls, it can be vaporized and new liquidcan be pushed against the wall of the cooling channels by the “core” ofvapor flowing down the middle of the passage. At low velocities, flowseparates based on gravity and liquid remains on the bottom of thecooling passage within the evaporator and vapor rises to the top side ofthe cooling passage channels. If the amount of area exposed to liquid isreduced by half, for example, this could cut the amount of heat transferalmost half. According to the American Society of Heating, Refrigeratingand Air-Conditioning Engineers (ASHRAE), a mass velocity of 150,000lb/hr ft{circumflex over ( )}2 maximizes performance for the majority ofthe evaporator flow path. Mass velocity is one of the parameters thatmust be balanced to optimize a refrigerant system. The parameters thataffect the performance of the evaporator are mass flow rate, convectiveheat transfer coefficient, and pressure drop. The nominal operatingpressure of the evaporator is determined by the required temperature ofthe evaporator and the properties of the refrigerant used in the system.The mass flow rate of refrigerant through the evaporator must be highenough for it to absorb the amount of thermal energy from the confectionto freeze it, in a given amount of time. Mass flow rate is primarilydetermined by the size of the compressor. It is desirable to use thesmallest possible compressor to reduce, cost, weight and size. Theconvective heat transfer coefficient is influenced by the mass velocityand wetted surface area of the evaporator. The convective heat transfercoefficient will increase with increased mass velocity. However,pressure drop will also increase with mass velocity. This in turnincreases the power required to operate the compressor and reduces themass flow rate the compressor can deliver. It is desirable to design theevaporator to meet performance objectives while using the smallest leastexpensive compressor possible. We have determined that evaporators witha mass velocity of 75,000-125,000 lb/hr ft{circumflex over ( )}2 areeffective in helping provide a system capable of freezing up to 12ounces of confection in less than 2 minutes. The latest prototype has amass velocity of approximately 100,000 lb/hr ft{circumflex over ( )}2and provides a good balance of high mass velocity, manageable pressuredrop in the system, and a reasonable sized compressor.

Another important factor that affects performance in an evaporator isthe surface area wetted by refrigerant which is the area of all thecooling channels within the evaporator exposed to refrigerant.Increasing the wetted surface area can improve heat transfercharacteristics of an evaporator. However, increasing the wetted surfacearea can increase the mass of the evaporator which would increasethermal inertia and degrade heat transfer characteristics of theevaporator.

The amount of heat that can be transferred out of the liquid in a pod isproportional to the surface area of the pod/evaporator heat transfersurface. A larger surface area is desirable but increases in surfacearea can require increasing the mass of the evaporator which woulddegrade heat transfer characteristics of the evaporator. We havedetermined that evaporators in which the area of the pod/evaporator heattransfer surface is between 20 and 40 square inches are effectivelycombined with the other characteristics to help provide a system capableof freezing up to 12 ounces of confection in less than 2 minutes.

Thermal conductivity is the intrinsic property of a material whichrelates its ability to conduct heat. Heat transfer by conductioninvolves transfer of energy within a material without any motion of thematerial as a whole. An evaporator with walls made of a highconductivity material (e.g., aluminum) reduces the temperaturedifference across the evaporator walls. Reducing this temperaturedifference reduces the work required for the refrigeration system tocool the evaporator to the right temperature.

For the desired heat transfer to occur, the evaporator must be cooled.The greater the mass of the evaporator, the longer this cooling willtake. Reducing evaporator mass reduces the amount of material that mustbe cooled during a freezing cycle. An evaporator with a large mass willincrease the time require to freeze up to 12 ounces of confection.

The effects of thermal conductivity and mass can be balanced by anappropriate choice of materials. There are materials with higher thermalconductivity than aluminum such as copper. However, the density ofcopper is greater that the density of aluminum. For this reason, someevaporators have been constructed that use high thermal conductivecopper only on the heat exchange surfaces of the evaporator and usealuminum everywhere else.

FIGS. 3A-3F show components of the pod-machine interface 106 that areoperable to open pods in the evaporator 108 to dispense the food ordrink being produced by the machine 100. This is an example of oneapproach to opening pods but some machines and the associated pods useother approaches.

FIG. 3A is a partially cutaway schematic view of the pod-machineinterface 106 with a pod 150 placed in the evaporator 108. FIG. 3B is aschematic plan view looking upwards that shows the relationship betweenthe end of the pod 150 and the floor 152 of the pod-machine interface106. The floor 152 of the pod-machine interface 106 is formed by adispenser 153. FIGS. 3C and 3D are perspective views of a dispenser 153.FIGS. 3E and 3F are perspective views of an insert 154 that is disposedin the dispenser 153. The insert 154 includes an electric motor 146operable to drive a worm gear 157 floor 152 of the pod-machine interface106. The worm gear 157 is engaged with a gear 159 with an annularconfiguration. An annular member 161 mounted on the gear 159 extendsfrom the gear 159 into an interior region of the pod-machine interface106. The annular member 161 has protrusions 163 that are configured toengage with a pod inserted into the pod-machine interface 106 to openthe pod. The protrusions 163 of the annular member 161 are fourdowel-shaped protrusions. Some annular gears have more protrusions orfewer protrusions and the protrusions can have other shapes, forexample, “teeth.”

The pod 150 includes a body 158 containing a mixing paddle 160 (see FIG.3A). The pod 150 also has a base 162 defining an aperture 164 and a cap166 extending across the base 162 (see FIG. 3B). The base 162 isseamed/fixed onto the body 158 of the pod 150. The base 162 includes aprotrusion 165. The cap 166 mounted over base 162 is rotatable aroundthe circumference/axis of the pod 150. In use, when the product is readyto be dispensed from the pod 150, the dispenser 153 of the machineengages and rotates the cap 166 around the first end of the pod 150. Cap166 is rotated to a position to engage and then separate the protrusion165 from the rest of the base 162. The pod 150 and its components aredescribed in more detail with respect to FIGS. 6A-10.

The aperture 164 in the base 162 is opened by rotation of the cap 166.The pod-machine interface 106 includes an electric motor 146 withthreading that engages the outer circumference of a gear 168. Operationof the electric motor 146 causes the gear 168 to rotate. The gear 168 isattached to a annular member 161 and rotation of the gear 168 rotatesthe annular member 161. The gear 168 and the annular member 161 are bothannular and together define a central bore through which food or drinkcan be dispensed from the pod 150 through the aperture 164 withoutcontacting the gear 168 or the annular member 161. When the pod 150 isplaced in the evaporator 108, the annular member 161 engages the cap 166and rotation of the annular member 161 rotates the cap 166.

FIG. 4 is a schematic of the refrigeration system 109 that includes theevaporator 108. The refrigeration system also includes a condenser 180,a suction line heat exchanger 182, an expansion valve 184, and acompressor 186. High-pressure, liquid refrigerant flows from thecondenser 180 through the suction line heat exchanger 182 and theexpansion valve 184 to the evaporator 108. The expansion valve 184restricts the flow of the liquid refrigerant fluid and lowers thepressure of the liquid refrigerant as it leaves the expansion valve 184.The low-pressure liquid-vapor mixture then moves to the evaporator 108where heat absorbed from a pod 150 and its contents in the evaporator108 changes the refrigerant from a liquid-vapor mixture to a gas. Thegas-phase refrigerant flows from the evaporator 108 to the compressor186 through the suction line heat exchanger 182. In the suction lineheat exchanger 182, the cold vapor leaving the evaporator 108 pre-coolsthe liquid leaving the condenser 180. The refrigerant enters thecompressor 186 as a low-pressure gas and leaves the compressor 186 as ahigh-pressure gas. The gas then flows to the condenser 180 where heatexchange cools and condenses the refrigerant to a liquid.

The refrigeration system 109 includes a first bypass line 188 and secondbypass line 190. The first bypass line 188 directly connects thedischarge of the compressor 186 to the inlet of the compressor 186.Disposed on the both the first bypass line and second bypass line arebypass valves that open and close the passage to allow refrigerantbypass flow. Diverting the refrigerant directly from the compressordischarge to the inlet can provide evaporator defrosting and temperaturecontrol without injecting hot gas to the evaporator. The first bypassline 188 also provides a means for rapid pressure equalization acrossthe compressor 186, which allows for rapid restarting (i.e., freezingone pod after another quickly). The second bypass line 190 enables theapplication of warm gas to the evaporator 108 to defrost the evaporator108. The bypass valves may be, for example, solenoid valves or throttlevalves.

FIGS. 5A and 5B are views of a prototype of the condenser 180. Thecondenser has internal channels 192. The internal channels 192 increasethe surface area that interacts with the refrigerant cooling therefrigerant quickly. These images show micro-channel tubing which areused because they have small channels which keeps the coolant velocityup and are thin wall for good heat transfer and have little mass toprevent the condenser for being a heat sink.

FIGS. 6A and 6B show an example of a pod 150 for use with the machine100 described with respect to FIGS. 1A-3F. FIG. 6A is a side view of thepod 150. FIG. 6B is a schematic side view of the pod 150 and the mixingpaddle 160 disposed in the body 158 of the pod 150. Other pod-machineinterfaces that can be used with this and similar machines are describedin more detail in U.S. patent application Ser. No. 16/459,176 filedcontemporaneously with this application and incorporated herein byreference in its entirety.

The pod 150 is sized to fit in the receptacle 110 of the machine 100.The pods can be sized to provide a single serving of the food or drinkbeing produced. Typically, pods have a volume between 6 and 18 fluidounces. The pod 150 has a volume of approximately 8.5 fluid ounces.

The body 158 of the pod 150 is a can that contains the mixing paddle160. The body 158 extends from a first end 210 at the base to a secondend 212 and has a circular cross-section. The first end 210 has adiameter D_(UE) that is slightly larger than the diameter D_(LE) of thesecond end 212. This configuration facilitates stacking multiple pods200 on top of one another with the first end 210 of one pod receivingthe second end 212 of another pod.

A wall 214 connects the first end 210 to the second end 212. The wall214 has a first neck 216, second neck 218, and a barrel 220 between thefirst neck 216 and the second neck 218. The barrel 220 has a circularcross-section with a diameter D_(B). The diameter D_(B) is larger thanboth the diameter D_(UE) of the first end 210 and the diameter D_(LE) ofthe second end 212. The first neck 216 connects the barrel 220 to thefirst end 210 and slopes as the first neck 216 extends from the smallerdiameter D_(UE) to the larger diameter D_(B) the barrel 220. The secondneck 218 connects the barrel 220 to the second end 212 and slopes as thesecond neck 218 extends from the larger diameter D_(B) of the barrel 220to the smaller diameter D_(LE) of the second end 212. The second neck218 is sloped more steeply than the first neck 216 as the second end 212has a smaller diameter than the first end 210.

This configuration of the pod 150 provides increased material usage;i.e., the ability to use more base material (e.g., aluminum) per pod.This configuration further assists with the columnar strength of thepod.

The pod 150 is designed for good heat transfer from the evaporator tothe contents of the pod. The body 158 of the pod 150 is made of aluminumand is between 5 and 50 microns thick. The bodies of some pods are madeof other materials, for example, tin, stainless steel, and variouspolymers such as Polyethylene terephthalate (PTE).

Pod 150 may be made from a combination of different materials to assistwith the manufacturability and performance of the pod. In oneembodiment, the pod walls and the second end 212 may be made of Aluminum3104 while the base may be made of Aluminum 5182.

In some pods, the internal components of the pod are coated with alacquer to prevent corrosion of the pod as it comes into contact withthe ingredients contained within pod. This lacquer also reduces thelikelihood of “off notes” of the metal in the food and beverageingredients contained within pod. For example, a pod made of aluminummay be internally coated with one or a combination of the followingcoatings: Sherwin Williams/Valspar V70Q11, V70Q05, 32SO2AD, 40Q60AJ; PPGInnovel 2012-823, 2012-820C; and/or Akzo Nobel Aqualure G1 50. Othercoatings made by the same or other coating manufacturers may also beused.

Some mixing paddles are made of similar aluminum alloys and coated withsimilar lacquers/coatings. For example, Whitford/PPG coating 8870 may beused as a coating for mixing paddles. The mixing paddle lacquer may haveadditional non-stick and hardening benefits for mixing paddle.

FIGS. 7A-7C illustrate the engagement between the driveshaft 126 of themachine 100 and the mixing paddle 160 of a pod 150 inserted in themachine 100. FIGS. 7A and 7B are perspective views of the pod 150 andthe driveshaft 126. In use, the pod 150 is inserted into the receptacle110 of the evaporator 108 with the first end 210 of the pod 150downward. This orientation exposes the second end 212 of the pod 150 tothe driveshaft 126 as shown in FIG. 7A. Closing the lid 112 (see FIG.1A) presses the driveshaft 126 against the second end 212 of the pod 150with sufficient force that the driveshaft 126 pierces the second end 212of the pod 150. FIG. 7B shows the resulting hole exposing the mixingpaddle 160 with the driveshaft 126 offset for ease of viewing. FIG. 7Cis a cross-section of a portion of the pod 150 with the driveshaft 126engaged with the mixing paddle 160 after the lid is closed. Typically,there is not a tight seal between the driveshaft 126 and the pod 150 sothat air can flow in as the frozen confection is evacuating/dispensingout the other end of the pod 150. In an alternative embodiment, there isa tight seal such that the pod 150 retains pressure in order to enhancecontact between the pod 150 and evaporator 108.

Some mixing paddles contain a funnel or receptacle configuration thatreceives the punctured end of the second end of the pod when the secondend is punctured by driveshaft.

FIG. 8 shows the first end 210 of the pod 150 with the cap 166 spacedapart from the base 162 for ease of viewing. FIGS. 9A-9D illustraterotation of the cap 166 around the first end 210 of the pod 150 to cutand carry away protrusion 165 of base 162 and expose aperture 164extending through the base 162.

The base 162 is manufactured separately from the body 158 of the pod 150and then attached (for example, by crimping or seaming) to the body 158of the pod 150 covering an open end of the body 158. The protrusion 165of the base 162 can be formed, for example, by stamping, deep drawing,or heading a sheet of aluminum being used to form the base. Theprotrusion 165 is attached to the remainder of the base 162, forexample, by a weakened score line 173. The scoring can be a verticalscore into the base of the aluminum sheet or a horizontal score into thewall of the protrusion 165. For example, the material can be scored froman initial thickness of 0.008 inches to 0.010 inches to a post-scoringthickness of 0.001 inches-0.008 inches. In an alternative embodiment,there is no post-stamping scoring but rather the walls are intentionallythinned for ease of rupture. In another version, there is not variablewall thickness but rather the cap 166 combined with force of the machinedispensing mechanism engagement are enough to cut the 0.008 inches to0.010 inches wall thickness on the protrusion 165. With the scoring, theprotrusion 165 can be lifted and sheared off the base 162 with 5-75pounds of force, for example between 15-40 pounds of force.

The cap 166 has a first aperture 222 and a second aperture 224. Thefirst aperture approximately matches the shape of the aperture 164. Theaperture 164 is exposed and extends through the base 162 when theprotrusion 165 is removed. The second aperture 224 has a shapecorresponding to two overlapping circles. One of the overlapping circleshas a shape that corresponds to the shape of the protrusion 165 and theother of the overlapping circles is slightly smaller. A ramp 226 extendsbetween the outer edges of the two overlapping circles. There is anadditional 0.020″ material thickness at the top of the ramp transition.This extra height helps to lift and rupture the protrusion's head andopen the aperture during the rotation of the cap as described in moredetail with reference to FIGS. 9A-9G.

As shown in FIGS. 9A and 9B, the cap 166 is initially attached to thebase 162 with the protrusion 165 aligned with and extending through thelarger of the overlapping circles of the second aperture 224. When theprocessor 122 of the machine activates the electric motor 146 to rotatethe gear 168 and the annular member 161, rotation of the cap 166 slidesthe ramp 226 under a lip of the protrusion 165 as shown in FIGS. 9C and9D. Continued rotation of the cap 166 applies a lifting force thatseparates the protrusion 165 from the remainder of the base 162 (seeFIGS. 9E-9G) and then aligns the first aperture 222 of the cap 166 withthe aperture 164 in the base 162 resulting from removal of theprotrusion 165.

Some pods include a structure for retaining the protrusion 165 after theprotrusion 165 is separated from the base 162. In the pod 150, theprotrusion 165 has a head 167, a stem 169, and a foot 171 (best seen inFIG. 9G). The stem 169 extends between the head 167 and the foot 171 andhas a smaller cross-section that the head 167 and the foot 171. Asrotation of the cap 166 separates the protrusion 165 from the remainderof the base 162, the cap 166 presses laterally against the stem 169 withthe head 167 and the foot 171 bracketing the cap 166 along the edges ofone of the overlapping circles of the second aperture 224. Thisconfiguration retains the protrusion 165 when the protrusion 165 isseparated from the base 166. Such a configuration reduces the likelihoodthat the protrusion falls into the waiting receptacle that when theprotrusion 165 is removed from the base.

Some pods include other approaches to separating the protrusion 165 fromthe remainder of the base 162. For example, in some pods, the base has arotatable cutting mechanism that is riveted to the base. The rotatablecutting mechanism has a shape similar to that described relative to cap166 but this secondary piece is riveted to and located within theperimeter of base 162 rather than being mounted over and around base162. When the refrigeration cycle is complete, the processor 122 of themachine activates an arm of the machine to rotate the riveted cuttingmechanism around a rivet. During rotation, the cutting mechanismengages, cuts and carries away the protrusion 165, leaving the aperture164 of base 162 in its place.

In another example, some pods have caps with a sliding knife that movesacross the base to remove the protrusion. The sliding knife is activatedby the machine and, when triggered by the controller, slides across thebase to separate, remove, and collect the protrusion 165. The cap 166has a guillotine feature that, when activated by the machine, may slidestraight across and over the base 162. The cap 166 engages, cuts, andcarries away the protrusion 165. In another embodiment, this guillotinefeature may be central to the machine and not the cap 166 of pod 150. Inanother embodiment, this guillotine feature may be mounted as asecondary piece within base 162 and not a secondary mounted piece as isthe case with cap 166.

Some pods have a dispensing mechanism that includes a pop top that canbe engaged and released by the machine. When the refrigeration cycle iscomplete, an arm of the machine engages and lifts a tab of the pod,thereby pressing the puncturing the base and creating an aperture in thebase. Chilled or frozen product is dispensed through the aperture. Thepunctured surface of the base remains hinged to base and is retainedinside the pod during dispensing. The mixing avoids or rotates over thepunctured surface or, in another embodiment, so that the mixing paddlecontinues to rotate without obstruction. In some pop tops, the arm ofthe machine separates the punctured surface from the base.

FIG. 10 is an enlarged schematic side view of the pod 150. The mixingpaddle 160 includes a central stem 228 and two blades 230 extending fromthe central stem 228. The blades 230 are helical blades shaped to churnthe contents of the pod 150 and to remove ingredients that adhere toinner surface of the body 158 of the pod 150. Some mixing paddles have asingle blade and some mixing paddles have more than two mixing paddles.

Fluids (for example, liquid ingredients, air, or frozen confection) flowthrough openings 232 in the blades 230 when the mixing paddle 160rotates. These openings reduce the force required to rotate the mixingpaddle 160. This reduction can be significant as the viscosity of theingredients increases (e.g., as ice cream forms). The openings 232further assist in mixing and aerating the ingredients within the pod.

The lateral edges of the blades 230 define slots 234. The slots 234 areoffset so that most of the inner surface of the body 158 is cleared ofingredients that adhere to inner surface of the body by one of theblades 230 as the mixing paddle 160 rotates. Although the mixing paddleis 160 wider than the first end 210 of the body 158 of the pod 150, theslots 234 are alternating slots that facilitate insertion of the mixingpaddle 160 into the body 158 of the pod 150 by rotating the mixingpaddle 160 during insertion so that the slots 234 are aligned with thefirst end 210. In another embodiment, the outer diameter of the mixingpaddle are less than the diameter of the pod 150 opening, allowing for astraight insertion (without rotation) into the pod 150. In anotherembodiment, one blade on the mixing paddle has an outer-diameter that iswider than the second blade diameter, thus allowing for straightinsertion (without rotation) into the pod 150. In this mixing paddleconfiguration, one blade is intended to remove (e.g., scrape)ingredients from the sidewall while the second, shorter diameter blade,is intended to perform more of a churning operation.

Some mixing paddles have one or more blades that are hinged to thecentral stem. During insertion, the blades can be hinged into acondensed formation and released into an expanded formation onceinserted. Some hinged blades are fixed open while rotating in a firstdirection and collapsible when rotating in a second direction, oppositethe first direction. Some hinged blades lock into a fixed, outward,position once inside the pod regardless of rotational directions. Somehinged blades are manually condensed, expanded, and locked.

The mixing paddle 160 rotates clockwise and removes frozen confectionbuild up from the pod 214 wall. Gravity forces the confection removedfrom the pod wall to fall towards first end 210. In the counterclockwisedirection, the mixing paddle 160 rotate, lift and churn the ingredientstowards the second end 212. When the paddle changes direction androtates clockwise the ingredients are pushed towards the first end 210.When the protrusion 165 of the base 162 is removed as shown anddescribed with respect to FIG. 9D, clockwise rotation of the mixingpaddle dispenses produced food or drink from the pod 150 through theaperture 164. Some paddles mix and dispense the contents of the pod byrotating a first direction. Some paddles mix by moving in a firstdirection and a second direction and dispense by moving in the seconddirection when the pod is opened.

The central stem 228 defines a recess 236 that is sized to receive thedriveshaft 126 of the machine 100. The recess and driveshaft 126 have asquare cross section so that the driveshaft 126 and the mixing paddle160 are rotatably constrained. When the motor rotates the driveshaft126, the driveshaft rotates the mixing paddle 160. In some embodiments,the cross section of the driveshaft is a different shape and the crosssection of the recess is compatibly shaped. In some cases the driveshaftand recess are threadedly connected. In some pods, the recess contains amating structure that grips the driveshaft to rotationally couple thedriveshaft to the paddle.

FIG. 11 is a flow chart of a method 250 implemented on the processor 122for operating the machine 100. The method 250 is described withreferences to refrigeration system 109 and machine 100. The method 250may also be used with other refrigeration systems and machines. Themethod 250 is described as producing soft serve ice cream but can alsobe used to produce other cooled or frozen drinks and foods.

The first step of the method 250 is to turn the machine 100 on (step260) and turn on the compressor 186 and the fans associated with thecondenser 180 (step 262). The refrigeration system 109 then idles atregulated temperature (step 264). In the method 250, the evaporator 108temperature is controlled to remain around 0.75° C. but may fluctuate by±0.25° C. Some machines are operated at other idle temperatures, forexample, from 0.75° C. to room temperature (22.0° C.). If the evaporatortemperature is below 0.5° C., the processor 122 opens the bypass valve190 to increase the heat of the system (step 266). When the evaporatortemperature goes over 1° C., the bypass valve 190 is closed to cool theevaporator (step 268). From the idle state, the machine 100 can beoperated to produce ice cream (step 270) or can shut down (step 272).

After inserting a pod, the user presses the start button. When the userpresses the start button, the bypass valve 190 closes, the evaporator108 moves to its closed position, and the motor 124 is turned on (step274). In some machines, the evaporator is closed electronically using amotor. In some machines, the evaporator is closed mechanically, forexample by the lid moving from the open position to the closed position.In some systems, a sensor confirms that a pod 150 is present in theevaporator 108 before these actions are taken.

Some systems include radio frequency identification (RFID) tags or otherintelligent bar codes such as UPC bar or QR codes. Identificationinformation on pods can be used to trigger specific cooling and mixingalgorithms for specific pods. These systems can optionally read theRFID, QR code, or barcode and identify the mixing motor speed profileand the mixing motor torque threshold (step 273).

The identification information can also be used to facilitate direct toconsumer marketing (e.g., over the internet or using a subscriptionmodel). This approach and the systems described in this specificationenable selling ice cream thru e-commerce because the pods are shelfstable. In the subscription mode, customers pay a monthly fee for apredetermined number of pods shipped to them each month. They can selecttheir personalized pods from various categories (e.g., ice cream,healthy smoothies, frozen coffees or frozen cocktails) as well as theirpersonalized flavors (e.g., chocolate or vanilla).

The identification can also be used to track each pod used. In somesystems, the machine is linked with a network and can be configured toinform a vendor as to which pods are being used and need to be replaced(e.g., through a weekly shipment). This method is more efficient thanhaving the consumers go to the grocery store and purchase pods.

These actions cool the pod 150 in the evaporator 108 while rotating themixing paddle 160. As the ice cream forms, the viscosity of the contentsof the pod 150 increases. A torque sensor of the machine measures thetorque of the motor 124 required to rotate the mixing paddle 160 withinthe pod 150. Once the torque of the motor 124 measured by a torquesensor satisfies a predetermined threshold, the machine 100 moves into adispensing mode (276). The dispensing port opens and the motor 124reverses direction (step 278) to press the frozen confection out of thepod 150. This continues for approximately 1 to 10 seconds to dispensethe contents of the pod 150 (step 280). The machine 100 then switches todefrost mode (step 282). Frost that builds up on the evaporator 108 canreduce the heat transfer efficiency of the evaporator 108. In addition,the evaporator 108 can freeze to the pod 150, the first portion 128 andsecond portion 130 of the evaporator can freeze together, and/or the podcan freeze to the evaporator. The evaporator can be defrosted betweencycles to avoid these issues by opening the bypass valve 170, openingthe evaporator 108, and turning off the motor 124 (step 282). Themachine then diverts gas through the bypass valve for about 1 to 10seconds to defrost the evaporator (step 284). The machine is programmedto defrost after every cycle, unless a thermocouple reports that theevaporator 108 is already above freezing. The pod can then be removed.The machine 100 then returns to idle mode (step 264). In some machines,a thermometer measures the temperature of the contents of pod 150 andidentifies when it is time to dispense the contents of the pod. In somemachines, the dispensing mode begins when a predetermined time isachieved. In some machines, a combination of torque required to turn themixing paddle, mixing motor current draw, temperature of the pod, and/ortime determines when it is time to dispense the contents of the pod.

If the idle time expires, the machine 100 automatically powers down(step 272). A user can also power down the machine 100 by holding downthe power button (286). When powering down, the processor opens thebypass valve 190 to equalize pressure across the valve (step 288). Themachine 100 waits ten seconds (step 290) then turns off the compressor186 and fans (step 292). The machine is then off.

FIG. 12 is a schematic of a refrigeration system 310 that includes theevaporator 108 and an expansion sub-system 312. The refrigeration system310 is substantially similar to the refrigeration system 109. However,the refrigeration system 310 includes the expansion sub-system 312rather than the expansion valve 184 shown in the refrigeration system109. The refrigeration system 310 does not include the first bypass line188 and the second bypass line 190 that are part of the refrigerationsystem 109. However, some systems include the with the expansionsub-system 312, the first bypass line, and the second bypass line.

The expansion sub-system 312 includes multiple valves to controlexpansion of the refrigeration fluid. These valves include a first fixedorifice valve 314, a second fixed orifice valve 316, and a control valve318. The control valve 318 is upstream from the second fixed orificevalve 316. The control valve 318 and second fixed orifice valve 316 arein parallel with the first fixed orifice valve 314. The expansion devicehas two modes to control the temperature of the refrigerant entering theevaporator 108. In the first mode, the control valve 318 is openallowing the refrigerant to flow to the second fixed orifice valve 316.In the first mode, the refrigerant flows through both the first fixedorifice valves 314 and the second fixed orifice valves 316. In thesecond mode, the control valve 318 is closed and the refrigerant doesnot flow through the second fixed orifice valve 316. All refrigerantflows through the first fixed orifice valve 314.

As discussed with reference to FIG. 4, the expansion valve 184 orexpansion sub-system 312 receives a high-pressure refrigerant andreleases low-pressure refrigerant. This pressure drop cools therefrigerant. Larger changes in pressure (ΔP) cause larger changes intemperature (ΔT). In the second mode (i.e., with control valve 318closed), the pressure drop through the expansion sub-system 312 will behigher than in the first mode providing a lower evaporator pressure andassociated lower evaporator temperature. The effect on heat transfer ofthe increased temperature differential between the refrigerant and thecontents of a pod in the evaporator 108 is offset to some extent by thefact that this lower pressure refrigerant is less dense. Since thecompressor moves a fixed volume of refrigerant each compression cycle,the mass flow per cycle is reduced, which lowers heat transfer. In thesecond mode of operation, there is a big temperature difference betweenthe pod and evaporator, requiring large heat transfer, which increasesthe amount of mass flow needed.

During initial operation, the refrigeration system 310 is in the firstmode. The control valve 318 is open and the refrigerant flows throughboth the first fixed orifice valve 314 and second fixed orifice valve316. This results in the evaporator operating at around a temperature of−20° C. to −10° C. At this temperature, the cooling system provides morecooling capacity than it can at lower temperatures by taking advantageof the higher density refrigerant passing through the evaporator.

The pod 150 is inserted into the evaporator 108 around room temperature(e.g., 22° C.). The initial difference in temperature between theevaporator 108 and the pod 150 is high. As a result, the heat transfersrapidly from the pod 150 to the evaporator 108. The difference betweenthe temperature of the pod 150 and the evaporator 108 decreases as thepod 150 cools and the transfer of heat from the pod 150 to theevaporator 108 also slows. At this point, the system 310 enters thesecond mode and the control valve 318 closes. The refrigerant flows onlythrough the first fixed orifice valve 314 and the ΔP between therefrigerant entering the first fixed orifice valve 314 and exiting thefirst fixed orifice valve 314 increases. The ΔT also increases resultingin a colder evaporator 108 with temperatures of approximately −15° C. to−30° C. This reduces the cooling capacity of the system, but increasesthe temperature difference between the pod and nest, which allows forquick final freezing of the ice cream. In the second mode activated whenthe temperature difference between the pod and evaporator reduces to thepoint of impacting heat transfer, the lower refrigerant temperatureaugments the overall heat transfer even through less mass is flowing inthe system.

In some embodiments, the temperature of the evaporator in the first modeis above freezing. This configuration can precool the evaporator beforeuse and defrost the evaporator after use.

The configuration of the refrigeration system 310 increases temperaturecontrol, which can reduce freezing time and reduce the requiredcompressor output. The reduction in required compressor output allowsfor a reduction in the size of the compressor.

In some refrigeration systems, the expansion sub-system includes morethan two valves. The multi-valve sub-systems can have more than twomodes, further increasing temperature control.

In some refrigeration systems use other types of valves such as, forexample, thermostatic expansion valves and electronic expansion valves.Both thermostatic expansion valves and electronic expansion valves canadapt the orifice size based on various loads and operating conditions.For example, the thermostatic expansion valves sense the evaporatoroutlet temperature of the refrigerant and adjusts flow through thethermostatic expansion valve to maintain predetermined or desiredoperating conditions. The electronic expansion valves are electricallyactuated to adapt the orifice size based on evaporator outlettemperature and electronic signals from a control unit 371.

FIG. 13 is a schematic of a refrigeration system 320 that includes arefrigerant line 322 that pre-chills a tank 324 of water prior toentering the evaporator 108. The refrigeration system 320 issubstantially similar to the refrigeration system 109. However, therefrigeration system 320 includes the pre-chilling line 322 and omitsthe first bypass line 188 and the second bypass line 190 that are partof the refrigeration system 109. Some systems include the first bypassline, the second bypass line, and the pre-chilling line.

The refrigeration system 320 is used in machines include the water tank324. Machines with water tanks inject fluid into the pod during mixing,for example, to dissolve dry ingredients or dilute the contents of thepod. Chilled water freezes more quickly than hot or room temperaturewater.

In use, a valve 326 is operated to route refrigerant throughpre-chilling to route refrigerant exiting the expansion valve 184through the pre-chilling line 322. The cold, low-pressure refrigerantflows through the pre-chilling line 322 that is partially or fullydisposed in the water tank 324. If the water tank 324 is filled withwater, the pre-chilling line 322 is partially or fully submerged in thewater. The refrigerant cools the water in the water tank 324 and exitsthe pre-chilling line 322. The refrigerant then enters the evaporator108 to cool the evaporator 108.

FIG. 14 is a schematic of a refrigeration system 328 that includes athermal mass 330 disposed between the compressor 186 and the condenser180. The refrigeration system 328 is substantially similar to therefrigeration system 109. However, the refrigeration system 328 includesthe thermal mass 330. The refrigeration system 328 does not include thefirst bypass line 188 and the second bypass line 190 that are part ofthe refrigeration system 109. Some systems include the first bypassline, the second bypass line, and the thermal mass 330.

The thermal mass may be, for example, ethylene glycol and water mixture,saltwater, paraffin wax (alkanes) or pure water. In some machines, thethermal mass 330 is disposed between the condenser 180 and heatexchanger 182.

The thermal mass 330 stores thermal energy and releases thermal energyat a later time. When disposed on between the compressor 186 and thecondenser 180, the thermal mass 330 stores heat emitted from therefrigerant. At this point in the cycle, the refrigerant is ahigh-pressure vapor. The condenser 180 isothermally releases heat fromthe high-pressure vapor to produce a high-pressure liquid. Precoolingthe vapor refrigerant with the thermal mass 330 reduces the load of thecompressor 186. When the machine 100 powers down, the thermal mass 330releases heat into the environment and reaches an equilibrium at ambienttemperatures.

Some systems include both the second bypass line and the thermal mass.The second bypass line redirects refrigerant from the thermal mass,idling the refrigeration system. During this idling period, the thermalmass releases heat from previous cycles into the environment.

FIG. 15 is a schematic of a refrigeration system 332 that includes apressure vessel 334, a first control valve 336, and a second controlvalve 338. The pressure vessel 334 can act as pressure reservoir thatenables rapid startup of the system and decreases the time required tocool (e.g., to freezing) contents of a pod in the evaporator 108. Therefrigeration system 332 is substantially similar to the refrigerationsystem 109. However, the refrigeration system 332 includes the pressurevessel 334, the first control valve 336, and the second control valve338. The refrigeration system 332 further does not include the firstbypass line 188 and the second bypass line 190 that are part of therefrigeration system 109. Some systems include the first bypass line,the second bypass line, the pressure vessel 334, the first control valve336, and the second control valve 338.

The first control valve 336 is disposed between the compressor 186 andthe condenser 180. The second control valve 338 is disposed between theheat exchanger 182 and the expansion valve 184. The pressure vessel 334is disposed between the condenser 180 and the heat exchanger 182. Therefrigerant exits the compressor 186 at a high-pressure and maintainsthat high-pressure until the liquid refrigerant is released by theexpansion valve 184. The system 332 controls the position of the valves336, 338 (e.g., open or closed) based on the desired outcome.

During normal operation of the system 332 (e.g., when cooling pods),both the first control valve 336 and the second control valve 338 areopen. Prior to idling, the second control valve 338 closes and the firstcontrol valve 336 remains open. The compressor 186 continues to run fora short time, for example, 1-5 seconds, before the first control valve336 closes. After the first control valve 336 closes, the compressorshuts down.

When the system 332 is reactivated (e.g., to produce a serving of acooled food or drink), the compressor 186 restarts, the first controlvalve 336 opens, and the second control valve 338 opens. Becausehigh-pressure fluid is already present in the pressure vessel 334,high-pressure refrigerant flows through the expansion valve 184 with thepressure drop cooling the refrigerant. This approach decreases the timerequired to cool the contents of a pod relative to refrigeration systemsthat allow to system pressures to return to ambient conditions whenshutting down. If the system is at ambient conditions, no pressure dropoccurs across the expansion valve initially when restarting the system.This approach has demonstrated to decrease the time required to cool thecontents of a 8-ounce pod from room temperature to freezing to less than90 seconds. The refrigeration system 332 is able to cool the refrigerantquickly or instantaneously when the system 332 initiates or boots up,for example prior to the insertion of a pod 150.

FIG. 16 is a schematic of a refrigeration system 340 that includes athermoelectric module 342. The refrigeration system 340 is substantiallysimilar to the refrigeration system 109. However, does not include thefirst bypass line 188 and the second bypass line 190 that are part ofthe refrigeration system 109. Some systems include the first bypassline, the second bypass line, and thermoelectric module 342.

Thermoelectric module 342 is a cooling element disposed between thecondenser 180 and the heat exchanger 182. The thermoelectric module 342cools the refrigerant that exits the condenser 180 prior to transferringheat to the refrigerant vapor exiting the evaporator 108 in the heatexchanger 182. Cooling the liquid refrigerant prior to expansionincreases the cooling capacity of the system 340 and reduce the requiredcompressor output. The reduction in required compressor output reducesthe size of the compressor needed.

FIG. 17 is a schematic of a refrigeration system 344 that includes athermal battery 346, a first battery bypass valve 348, and a secondbattery bypass valve 350. The refrigeration system 344 is substantiallysimilar to the refrigeration system 109 but does not include the firstbypass line 188 that is part of the refrigeration system 109. Somesystems with the thermal battery 346 and associated valves also includesthe first bypass line.

The thermal battery 346 has a first portion 352 that is disposed betweenthe heat exchanger 182 and the expansion valve 184. The first batterybypass valve 348 is disposed on a first branch line 354 that bypassesthe first portion 352 of the thermal battery 346. When the first batterybypass valve 348 is open, a majority or all the refrigerant flowsthrough the first branch line 354. The thermal battery 346 has a highpressure drop. The refrigerant primarily flows through the branch line354 because the branch line 354 has a comparatively low pressure drop tothe thermal battery 346. When the first battery bypass valve 348 isclosed, the refrigerant flows through the first portion 352 of thethermal battery 346.

The thermal battery 346 has a second portion 356, thermally connected tothe first portion 352, that is disposed between the evaporator 108 andthe heat exchanger 182. The second battery bypass valve 350 is disposedon a second branch line 358 that bypasses the second portion 356 of thethermal battery 346. When the second battery bypass valve 350 is open amajority or all of the refrigerant flows through the second branch line358. The thermal battery 346 has a high pressure drop. The refrigerantprimarily flows through the branch line 358 because the branch line 358has a comparatively low pressure drop to the thermal battery 346. Whenthe second battery bypass valve 350 is closed, the refrigerant flowsthrough the second portion 356 of the thermal battery 346.

The thermal battery 346 includes a thermal material that retains heat.The thermal battery 346 includes a reservoir 360 with a phase changematerial (e.g., paraffin) receives heat or emits heat, depending on theposition of the first battery bypass valve 348 and the second batterybypass valve 350. The thermal battery 346 is described as using paraffinas an example of a phase change material. Some thermal batteries includeother materials that retain heat or expend heat, for example ethyleneglycol and water mixture, saltwater or pure water.

The thermal battery 346 emits heat from its second portion 356 to therefrigerant when the first battery bypass valve 348 is open and thesecond battery bypass valve 350 is closed. If the paraffin is warm ormelted, the cold refrigerant will chill and solidify the paraffin in thereservoir 360. By heating the low-pressure refrigerant, the thermalbattery reducing the likelihood that liquid refrigerant will flow intothe compressor.

The thermal battery 346 receives heat at the first portion 352 from therefrigerant when the first battery bypass valve 348 is closed and thesecond battery bypass valve 350 is open. If the wax is solidified, thehot liquid refrigerant will heat and melt the wax in the wax reservoir360. If the wax is liquid, the hot refrigerant will continue to heat theliquid wax in the wax reservoir 360.

On activation of the system 344 and during the cooling cycle, both thefirst battery bypass valve 348 and the second battery bypass valve 350are open and little to no refrigerant flows interacts with the thermalbattery 346. At the end of the cooling cycle, the second battery bypassvalve 350 closes and the reservoir 360 cools due to the cold,low-pressure refrigerant. As the next cycle begins with a cooledbattery, the second battery bypass valve 350 opens, and the firstbattery bypass valve 348 closes. The first portion 352 of the thermalbattery 346 then pre-cools the hot liquid refrigerant exiting thecondenser 180 via the heat exchanger 182.

This configuration can prevent end-of-cycle compressor flooding and canreduce the output of the compressor by reducing the heat load on thecompressor. Some waxes may have a melting point in a range of 5° C.-10°C., for example, Dodecane wax or Tridecane wax.

FIG. 18A is top view of an evaporator cover 127 and FIG. 18B is a topview of the body of the evaporator 108. The body of the evaporator 108defines the channels 366 through which refrigerant flows to cool theevaporator 108. The channels 366 are open at a lip 367, as shown in FIG.18B, of the evaporator 108. The channels 366 are also open at theopposite end of the evaporator 108 with a similarly configured lip.

The cover 127 includes multiple recesses 174 that align with fouradjacent channels 366 of the evaporator 108 when the cover 127 isattached to the body of the evaporator 108. Some covers include recessesthat align with other numbers of adjacent channels. The recesses 174 actas manifolds fluidly connect the adjacent channels 366. The cover 127 onthe opposite ends of the body of the evaporator are offset so that thetwo covers 127 and the body of the evaporator 108 together define aserpentine flow path through the evaporator 108.

The cover 127 has an inlet 370 and an outlet 372 that fluidly connectsthe evaporator 108 to the refrigeration system 109. Refrigerant flowsthrough the inlet 370, through the channels defined by recesses in thebody of the evaporator 108 and the cover 127, and exits the evaporator108 through the outlet 372. The refrigerant enters the inlet 370 as acold fluid at a first temperature. As the refrigerant flows through theflow path 368, the refrigerant warms and evaporates due to the heatreceived by the evaporator 108 from the pod 150. The pod 150 freezes dueto this heat transfer. To maintain a constant flow speed, the inlet 370is about 0.25 inches in diameter and the outlet 372 is about 0.31 inchesin diameter.

The living hinge 132 defines a connecting channel 373 that fluidlyconnects channels in the first portion 128 of the evaporator 108 tochannels 366 in the second portion 130 of the evaporator 108. Theconnecting channel 373 is defined within the evaporator 108 near the lip367 of the evaporator 108. In some evaporators, the lip of theevaporator defines a groove and the lid defines a corresponding grooveso that the connecting channel is formed between the groove of the lidand the groove of the evaporator, when the lid and evaporator engage.Some connecting channel are defined within the cover 127. Thisconfiguration defines the continuous flow path 368 from the inlet 370 tothe outlet 372 in which channels 366 extend parallel to the axis 369 andflow fluid parallel to the axis 369.

In some evaporators, the channels 366 connect within the evaporator atthe opposite end from the lip 367, to form a “U” shape. When assembled,the cover 127 is disposed on the lip 367 of the evaporator 108. Thechannels 366 are a series of unconnected “U” shaped units. In each unit,a first channel flows the refrigerant in a first direction and a secondchannel flows the fluid in a second direction, opposite the firstdirection.

The channels 366 extend parallel to an axis 369 of the evaporator. Insome evaporators, the channels do not extend parallel to the axis but doextend parallel to each other. In some evaporators, the channels do notextend parallel to each other or parallel to the axis.

FIGS. 19A and 19B are perspective views of an evaporator 380 without andwith, respectively, its cover 127. The evaporator 380 in FIGS. 19A and19B operates similarly to the evaporator 108 described in FIGS. 18A-18E.However, the evaporator 380 includes recesses 382 that fluidly connectthe second channel 366 b of a unit 371 to a first channel 366 a of adifferent unit 371. The cover 384 is substantially similar to the cover127. However, the cover 384 is flat rather than recessed on the surfacethat abuts the lip 367, and includes multiple inlets and outlets, ratherthan a single inlet and a single outlet. The cover 384 includes a firstinlet 388 on the first portion 128, a first outlet 390 on the firstportion 128, a second inlet 392 on the second portion 130, and a secondoutlet 394 on the second portion. The first inlet 388 and first outlet390 are fluidly connected to form a first flow path 396 on the firstportion 128. The second inlet 392 and second outlet 394 fluidly connectto form a second flow path 398 on the second portion 130. Thisconfiguration forms two flow paths 396, 398 that flow refrigerant inparallel and does not use a hinge connector. To maintain flow speed, thediameters of the flow paths 396, 398 are reduced such that the dividedflow paths have a similar flow area to the originating flow path.

When the cover 384 engages the evaporator 380, the recesses 382 areclosed and the evaporator 380 and cover 384 form the flow paths 396,398.

In the previously described evaporators, the units 371 have“One-up/One-down” configurations. In some evaporators, the units define“Two-Up/Two-Down” or “Three-Up/Three-Down” configurations. This canmaintain proper flow speeds while minimizing the pressure drop withinevaporator. Different flow path arrangements are needed for differentcompressors and different cooling tasks. The number of parallel flowpaths can be increased for larger compressors and cooling loads and bereduced for smaller requirements.

FIGS. 20A-20D are schematic views of flow paths formed by the channelsof the evaporator and recesses of its cover 127. FIGS. 20A and 20B areviews of the channels defined within an evaporator. FIGS. 20C and 20Dare perspective views of an evaporator and its cover 127.

FIG. 20A is a flow path 402 that increases the number of channels 400 asthe refrigerant evaporates. The refrigerant enters the inlet and flowsthrough one or more single channels 400 a. At the refrigerantevaporates, it expands in volume and begins to move faster. The vapormay expand about 50-70 times in specific volume. To slow the mixed-phaserefrigerant within the evaporator 108, the flow path 402 branches intotwo parallel channels 400 b that connect at the recesses 374 and withinthe evaporator 108 at a turning point 306. As the refrigerant evaporatesmore, the flow path 402 branches again into three parallel channels 400c that connect at the recesses 374 and within the evaporator 108 at theturning point 306. In some evaporators, the “Two-Up/Two-Down”configuration is maintained for multiple units. In some evaporators, the“Three-Up/Three-Down” configuration is maintained for multiple units. Insome evaporators, the flow path increase to a “Four-Up/Four-Down” or“Five-Up/Five-Down” configuration. Increasing the number of channelsthroughout the evaporator increases performance early in the evaporatingprocess while limiting high velocity/pressure drop towards the outlet ofthe evaporator.

FIG. 20B is a schematic of the flow path 402 with a ramped recess 408 inthe cover 127 that acts as a manifold. The ramped recess 408 has asmoothly increasing and decreasing cross-sectional area that helpsmaintains the flow speed of refrigerant flowing through manifold. Aramped cross section recess in the cover would help maintain flowvelocities and also reduce pressure drop and flow separation of liquidand gas refrigerant due to low flow velocity areas.

FIG. 20C shows a flow path 420 that includes a first manifold at thebottom of the evaporator 108 and multiple branches 424 extending towardsthe cover 127 from the first manifold 422. The first manifold 422connects to the inlet 370. The branches 424 fluidly connect to a secondmanifold 426 at the top of the evaporator 108. The second manifold 426fluidly connects to the outlet 372.

The refrigerant flows from the inlet through the first manifold 422, upthe branches 424, and through the second manifold 426 to the outlet 372.Vapor is less dense that the liquid and tends to rise to the top. Thispreferential flow direction can create unpredictable flow andperformance when flow direction is downward. This configuration canincrease thermal performance of the evaporator 108 by flowingrefrigerant the in the same direction as the buoyancy force present whenthe refrigerant is in vapor form.

FIG. 20D shows a flow path 430 that winds around the evaporator 108. Theflow path 430 is a spiral that follows the outer diameter of theevaporator 108. This configuration increases surface area and reducespressure drop by reducing or eliminating tight turns in the flow path430. In some evaporators, multiple hinge connectors are used to connectthe first portion of the evaporator and the second portion of theevaporator when the flow path extends across the first and secondportion Some flow paths define a serpentine passage on the first portionand a serpentine passage on the second portion that are connected by a“transit passage” that spans the hinge.

FIGS. 21A-21C are views of the pod 150 and an evaporator 438 with aclosing mechanism 440. FIG. 21A is a perspective view of the evaporator438 and pod 150. FIG. 21B is a cross-sectional view of the pod 150 andthe evaporator 438. FIG. 21C is a top view of the pod 150 and theevaporator 438.

The closing mechanism 440 includes biasing elements (e.g. springs) thatconnects the first portion 128 of the evaporator 438 to the secondportion 130 of the evaporator 438. The closing mechanism 440 alsoincludes a circumferential cable 441 that extends around the outerdiameter of the evaporator. The cable is tightened close the pod andloosened to open the evaporator.

The biasing element in evaporator 438 includes a first and second spring442, 444 that bias the first portion 128 and the second portion 130 awayfrom each other. The living hinge 132 facilitates the movement of thefirst and second portions 128, 130 such that the first and secondportions 128, 130 rotation about the hinge 132 due to the biasing forceof the springs 442, 444. In this configuration, the evaporator 438 is inthe open position and a small gap 446 forms between the first and secondportions 128, 130. The evaporator 438 is in the open position when thecover 127 is in the open position. In some machines, the position of theevaporator is independent from the position of the lid. In the openposition, a small air gap exists between the evaporator 438 and the pod150.

The evaporator 438 has a closed position in which the airgap between theevaporator 438 and the pod 150 is eliminated to promote heat transfer.In some evaporators, the air gap is simply reduced. In the closedposition, the gap 446 is also eliminated. In some evaporators, the gapis reduced rather than eliminated. To move from the open position to theclosed position, the closing mechanism 440 applies a force in thedirection of arrows 448 to overcome the biasing force of the first andsecond springs 442, 444.

The closing mechanism produces a force within the range of 10 to 1500lbs. To prevent crushing of the pod 150, the internal pressure of thepod 150 is preferably equal to or greater than the force produced by theclosing mechanism 440.

The closing mechanism 440 may be, for example, an electromechanicalactuator, a pulley system, a lever, projections on the lid, a ballscrew, a solenoid, or a mechanical latch.

FIGS. 22A and 22B are, respectively, side and front views of anevaporator 108 with a closing mechanism 440 that includes two bolts 450inside springs 456. The bolts 450 bias the bar 466 away from flanges464. Optionally, a cable 468 is received in a hole defined in the bar466 and extends around the evaporator 108.

FIG. 23A shows an evaporator 500 that can be produced primarily byextrusion. The evaporator 500 has a body 510 with two end caps 512. Thebody 510 and the end caps are produced separately and then assembled.

FIGS. 23B and 23C illustrate production of the body 510. The evaporatorbody 510 is produced by low cost extrusion. The body is extruded withthe channels 514 defined in the body 510 (see FIG. 23B). Each end of thebody 510 is machined to provide a shoulder 516 that mates with an endcap (see FIG. 23C). A wall 518 extends beyond the shoulder 516.

FIGS. 23D and 23E are perspective views of an end cap 512. The end caps512 can be forged or machined. The end caps 512 provide the mounting,inlet/outlet, and closure features of the evaporator 500. The end cap512 has a sidewall 520 and an end wall 522.

The end cap 512 has multiple bosses 524 extending outward from thesidewall 520. The bosses 524 can be used for mounting and handling theend cap 512 and, after assembly with the body 510, the evaporator 500. Aport 526 extends through the sidewall 520. The port 526 of the end cap512 on one end of the evaporator 500 is used as an inlet and the port526 of the end cap 512 on the other end of the evaporator 500 is used asan outlet.

FIG. 23F illustrates assembly of the evaporator 500. The end cap 512 ismounted on the shoulder 516 on one end of the body 510. After mounting,the joints between the evaporator body 510 and the end caps 512 areeasily accessible. This configuration facilitates use of used for laserwelding, vacuum brazing, friction stir welding or TIG welding to attachthe end caps 512 to the evaporator body 510.

FIGS. 23G and 23H illustrate the relationship between the body 510 andthe end cap 512 after assembly. When assembled with the body 510, thesidewall 520 and the end wall 522 of the end cap and the wall 518 of thebody 510 define a chamber that acts as a manifold connecting thechannels defined in the body 510 of the evaporator 500. The end cap 512is shown with “hollow” configuration for evaporating up with allpassages in parallel but it could be adapted for a multipath design withmultiple 180 degree turnarounds.

FIG. 24 shows a configuration of the evaporator 500 that incorporates anorifice plate 530. The orifice plate 530 is disposed between the body510 and the end cap 512. The orifice plate 530 defines multiple orifices532 that, after assembly, are aligned with the channels 514 in the body510. The orifice plate can be used to distribute flow evenly to thechannels 514 by accumulating refrigerant prior to the orifice plate 530and injecting liquid-gas mixture equally to the channels 524. In somecases, the orifices are identical in size. In some cases, where there islikely to be maldistribution of flow between passages 514, the orificescan be different sizes.

FIG. 25 is a perspective view of an embodiment of the evaporator 380described with reference to FIGS. 19A and 19B with an internal surface470 made of a different material than the remainder of the evaporator380. The inner surface 470 is mainly or completely formed of copper.Copper has a higher thermal conductivity (approximately 391 W/mK) thanaluminum that has a thermal conductivity of 180 W/mK. A high thermalconductivity moves heat quickly and efficiently from the pod to therefrigerant. A material with low thermal conductivity pass heat slowerand with less efficiency. The tendency of a component to act as a heatsink is a function of both its thermal conductivity and its mass. Table2 lists the thermal conductivity and density of a variety of materials.

TABLE 2 Conductivity under standard conditions (atmospheric pressure and293 degrees Kelvin) Thermal conductivity Material [W · m⁻¹ · K⁻¹]Acrylic glass (Plexiglas V045i) 0.170-0.200 Alcohols, oils 0.100Aluminium 237 Alumina 30 Boron arsenide 1,300 Copper (pure) 401 Diamond1,000 Fiberglass or foam-glass 0.045 Polyurethane foam 0.03 Expandedpolystyrene 0.033-0.046 Manganese 7.810 Water 0.5918 Marble 2.070-2.940Silica aerogel 0.02 Snow (dry) 0.050-0.250 Teflon 0.250

FIGS. 26A-26C are schematic views of claddings. These claddings can beused in an evaporator that includes both aluminum and copper. FIG. 26Ashows an overlay cladding 490. FIG. 26B shows an inlay clad 492. FIG.26C shows an edge clad 495. Cladding techniques as shown in FIGS.26A-26C are applied to the inner surface of the evaporator. Differentclad techniques can increase heat transfer and spread heat out, due tothe high thermal conductivity of copper.

FIG. 27 is an exemplary view of a material 480 that includesmicrochannels 482. When the material 480 is used to make, for example,evaporators, refrigerant flows through the microchannels 482. Thematerial 480 can be bent to form an evaporator that cools the pod 150.The material 480 is permanently deformed into a cylindrical shape tocreate a round evaporator. Such an evaporator has a high surface areawhich increases evaporator performance while keep costs low.

FIGS. 28A-28C show a rotary compressor 550 that is used in some somerefrigeration systems instead of the reciprocating compressor 186previously described. The compressor 550 includes a housing 552 with aninterior wall 553 that defines an interior cavity 554. An inlet 556 andan outlet 558 fluidly connect the interior cavity 554 of the compressor550 to other components of the refrigeration system. A pressure valve559 releases fluid when the fluid reaches a predetermined pressure. Aroller 560 with a circular cross section, is rotationally and axiallyconstrained to a rod 562 that extends through a bottom section of thehousing 552. Some rollers have ellipse shaped or gear shaped crosssections. The rod 562 is attached off center from the circular crosssection of the roller 560. The rod 562 and roller 560 rotate relative tothe housing 557 using a motor (not shown). The roller 560 is arranged inthe cavity 554 such that an edge 564 of the roller 560 extends to theinterior wall 553 of the housing. In this configuration, the roller 560forms a seal with the housing 557. The edge 564 of the roller 560maintains contact on the wall 553 as the rod 562 and the roller 560rotate within the interior cavity 554. The housing 557 includes anotched area 566 for containing a compressed spring 568. The spring 568abuts the roller 560. A rubber member 570 surrounds a portion of thespring 568 to form a seal that extends from the wall 553 to the roller560. The spring 568 expands and contracts as the roller 560 rotateswithin the interior cavity 554, to maintain the seal.

In FIG. 28A, the compressor 550 is in a first state. In FIG. 28B, therotary compressor 550 is in a second state and in FIG. 28C, the rotarycompressor 550 is in a third state. The rotary compressor 550 moves fromthe first state to the second state, from the second state to the thirdstate, and from the third state to the first state. In the first state,the roller 560 receives low-pressure pressure cool vapor from theevaporator 108 via the inlet 556. The seal between the contact edge 564and the wall 553 and the seal between the member 570 and the roller 560define an intake chamber 572 and a pressurizing chamber 574. In somerotary compressors, additional seals are formed that increase the numberof chambers. The roller 560 rotates to compress and pressurize vapor inthe pressurizing chamber 574 and to draw in vapor to intake chamber 572from the inlet 556. In the second state, shown in FIG. 28B, the roller560 continues to rotate counterclockwise and increase the pressure ofthe vapor in the pressurizing chamber 574 until the pressure valve 559releases the high-pressure vapor out of the compressor 550. The intakechamber continues to receive low-pressure vapor from the inlet 556. Thecompressed spring 568 extends into the interior cavity 554 as the roller560 rotates, to maintain connection between the member 570 and theroller 560. In the third state, shown in FIG. 28C, the high-pressurevapor has been expelled from the pressurizing chamber 574 and the spring568 is compressed into the notched area 566. In this state, only oneseal is formed between the contact edge 564 and the member 570. For abrief period in the cycle the number of chambers is reduced by one. Atthis state in the compressor 550, the intake chamber 572 becomes thepressurizing chamber 574. The intake chamber 572 is reformed when thecontact edge 564 passes the member 570 and two seals are formed, one bythe member 570 and roller 560 and the other by the contact edge 564 andthe wall 553.

The rotary compressor performs the same thermal duty as thereciprocating compressor at a much lower weight and smaller size. Therotary compressor has a weight of about 10 to about 18 lbs. The rotarycompressor has a displacement of refrigerant of about 4 cc to about 8cc. The rotary compressor has a performance vs. weight ratio of about0.3 cc/lb to about 0.5 cc/lb.

A number of embodiments of the invention have been described.Nevertheless, it will be understood that various modifications may bemade without departing from the spirit and scope of this disclosureinvention. Accordingly, other embodiments are within the scope of thefollowing claims.

What is claimed is:
 1. A machine for producing cooled food or drinksfrom ingredients in a pod containing the ingredients, the machinecomprising: an evaporator of a refrigeration system, the evaporatordefining a receptacle sized to receive the pod, wherein therefrigeration system has a working fluid loop that runs from theevaporator, to a compressor, to a condenser, to an expansion device,back to the evaporator, and also includes a first bypass line thatextends from the working fluid loop between the compressor and thecondenser to the working fluid loop between the expansion device and theevaporator; and a processor operable to control the refrigeration systemto cool the pod after the pod is inserted in the receptacle of theevaporator and to defrost a surface of the evaporator after the cooledfood or drinks are dispensed from the pod and before the pod is removedfrom the receptacle of the evaporator.
 2. The machine of claim 1,further comprising a bypass valve on the first bypass line.
 3. Themachine of claim 1, further comprising a second bypass line that extendsfrom the working fluid loop between the compressor and the condenser tothe working fluid loop between the evaporator and the compressor.
 4. Themachine of claim 3, further comprising a bypass valve on the secondbypass line.
 5. The machine of claim 3, further comprising a suctionline heat exchanger.
 6. The machine of claim 5, wherein the workingfluid loop passes through a reservoir of phase change material disposedbetween the compressor and the condenser.
 7. The machine of claim 6,wherein the phase change material comprises an ethylene glycol and watermixture, salt water, paraffin wax, alkanes, or pure water or acombination thereof.
 8. The machine of claim 7, wherein the workingfluid loop includes a pressure vessel between the condenser and theevaporator, a first isolation valve between the pressure vessel and theexpansion valve, and a second isolation valve between the compressor andthe condenser.
 9. The machine of claim 8, wherein the working fluid looppasses through a thermoelectric cooler between the condenser and theexpansion valve.
 10. A machine for reducing the temperature ofingredients in a pod containing the ingredients and at least one mixingpaddle, the machine comprising: an evaporator of a refrigeration system,the evaporator defining a receptacle sized to receive the pod, whereinthe refrigeration system has a working fluid loop that runs from theevaporator, to a compressor, to a condenser, to an expansion device,back to the evaporator, and also includes a first bypass line thatextends from the working fluid loop between the compressor and thecondenser to the working fluid loop between the expansion device and theevaporator and a bypass valve on the first bypass line; a motor operableto move the at least one mixing paddle of a pod in the receptacle; and aprocessor operable: to close the bypass valve on the first bypass lineand operate the motor to rotate the at least one mixing paddle while theevaporator freezes the ingredients in the pod in the receptacle of theevaporator and the cooled food or drink from the pod is dispensed out ofthe pod through an aperture in the pod; and to open the first bypassline to defrost the surface of the receptacle of the evaporator whilethe pod is in the receptacle of the evaporator.
 11. The machine of claim10, wherein the working fluid loop includes a pressure vessel betweenthe condenser and the evaporator, a first isolation valve between thepressure vessel and the expansion valve, and a second isolation valvebetween the compressor and the condenser.
 12. The machine of claim 10,wherein the working fluid loop passes through a thermoelectric coolerbetween the condenser and the expansion valve.
 13. The machine of claim10, wherein the processor is operable to open the first bypass line todefrost the surface of the receptacle of the evaporator after the cooledfood or drink from the pod is dispensed out of the pod through theaperture in the pod.
 14. The machine of claim 10, further comprising asecond bypass line that extends from the working fluid loop between thecompressor and the condenser to the working fluid loop between theevaporator and the compressor.
 15. The machine of claim 14, furthercomprising a bypass valve on the second bypass line.
 16. The machine ofclaim 14, further comprising a suction line heat exchanger.
 17. Themachine of claim 14, wherein the working fluid loop passes through areservoir of phase change material disposed between the compressor andthe condenser.
 18. The machine of claim 17, wherein the phase changematerial comprises an ethylene glycol and water mixture, salt water,paraffin wax, alkanes or pure water.
 19. A machine for producing cooledfood or drinks from ingredients in a pod containing the ingredients, themachine comprising: a housing; and an evaporator of a refrigerationsystem, the evaporator defining a receptacle sized to receive the pod,the evaporator having a pod-to-evaporator heat transfer surface of theevaporator of less than 50 square inches, and the evaporator isconstructed of material defining microchannels; wherein therefrigeration system has a working fluid loop that runs from theevaporator, to a compressor, to a condenser, to an expansion device, andback to the evaporator; and wherein the evaporator is made of a materialthat has at least 160 W/mK thermal conductivity.
 20. The machine ofclaim 19, further comprising an aluminum evaporator with a mass of lessthan 1.50 pounds.
 21. The machine of claim 19, wherein the evaporatorhas cooling channels in it allowing for the fluid mass velocity up to180,000 lb/(hour feet squared).
 22. The machine of claim 19, furthercomprising an evaporator refrigerant wetted surface area of less than200 square inches.
 23. The machine of claim 19, wherein the evaporatorclamps down on the pod.
 24. The machine of claim 19, wherein theevaporator has an internal wall of copper adjacent to the pod.
 25. Themachine of claim 19, further comprising a bypass line that extends fromthe working fluid loop between the compressor and the condenser to theworking fluid loop between the expansion valve and the evaporator. 26.The machine of claim 19, further comprising a rotary compressor withdisplacement of refrigerant of less than 6 cubic centimeters.
 27. Themachine of claim 19, further comprising R-290 propane as a refrigerant.28. The machine of claim 19, wherein a pressure drop across theevaporator is less than 2 psi.
 29. A method of reducing the temperatureof ingredients in a pod containing the ingredients, the methodcomprising: inserting the pod containing the ingredients into anevaporator of a refrigeration system of a machine, the refrigerationsystem having a working fluid loop that runs from the evaporator, to acompressor, to a condenser, to an expansion device, back to theevaporator, and also includes a first bypass line that extends from theworking fluid loop between the compressor and the condenser to theworking fluid loop between the expansion device and a bypass valve onthe first bypass line; operating a motor of the machine to rotate amixing paddle inside the pod while using the evaporator to cool the podwith a bypass valve on the first bypass line closed; operating the motorof the machine to rotate the mixing paddle inside the pod whiledispensing the cooled food or drink out of the pod through an aperturein the pod; and opening the first bypass line to defrost the surface ofthe receptacle of the evaporator while the pod is in the receptacle ofthe evaporator.
 30. The method of claim 29, opening a second valve on asecond bypass line that extends from the working fluid loop between thecompressor and the condenser to the working fluid loop between theevaporator and the compressor.
 31. The method of claim 29, wherein therefrigeration cycle has a suction line heat exchanger.
 32. The method ofclaim 29, wherein the working fluid loop includes a pressure vesselbetween the condenser and the evaporator, a first isolation valvebetween the pressure vessel and the expansion valve, and a secondisolation valve between the compressor and the condenser.
 33. The methodof claim 29, wherein the working fluid loop passes through athermoelectric cooler between the condenser and the expansion valve. 34.The method of claim 29, wherein opening the first bypass line to defrostthe surface of the receptacle of the evaporator while the pod is in thereceptacle of the evaporator comprises opening the first bypass line todefrost the surface of the receptacle of the evaporator after the cooledfood or drink from the pod is dispensed out of the pod through theaperture in the pod.
 35. The method of claim 29, wherein the workingfluid loop passes through a reservoir of phase change material disposedbetween the compressor and the condenser.
 36. The method of claim 35,wherein the phase change material comprises ethylene glycol and watermixture, salt water, paraffin wax, alkanes or pure water.